Semiconductor Withstand Voltage Improvement Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices face challenges in achieving high withstand voltages without affecting transistor characteristics, as lowering impurity concentration to expand the depletion layer can lead to decreased threshold voltage due to the short channel effect in miniaturized transistors.
Innovation Solution
A withstand voltage improvement layer with an impurity diffusion layer of the same conductivity type as the drain is introduced, isolated from the transistor circuit elements, which expands the depletion layer by applying a voltage within a specific range, thereby increasing the maximum withstand voltage without affecting transistor characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If impurity concentration is lowered to expand the depletion layer, then withstand voltage is improved, but threshold voltage decreases due to short channel effect
Solution Approach 1:
The invention divides the semiconductor device into functionally independent regions: the transistor active region and the withstand voltage improvement layer. By segmenting the depletion layer expansion function into a separate layer with its own impurity diffusion region, the patent allows the transistor region to maintain its original impurity concentration and threshold voltage characteristics, while the improvement layer independently provides enhanced withstand voltage through controlled depletion layer expansion.
Solution Approach 2:
The withstand voltage improvement layer acts as an intermediary structure between the transistor and the high voltage stress. This intermediate layer, with its specific impurity concentration and depletion layer characteristics, mediates the voltage stress, allowing the main transistor to operate at normal threshold voltages while the improvement layer handles the high voltage protection function.
2Strength
If impurity concentration is lowered to expand the depletion layer, then maximum withstand voltage increases, but transistor characteristics are affected
Solution Approach 1:
The patent segments the voltage handling function from the transistor operation function by creating a separate withstand voltage improvement layer. This layer has optimized impurity concentration for maximum withstand voltage, while the transistor maintains its original characteristics. The segmentation allows independent optimization of each function without compromise.
Solution Approach 2:
The invention applies local quality by creating a region with specific impurity concentration characteristics tailored for withstand voltage improvement, distinct from the transistor region. The withstand voltage improvement layer has locally optimized impurity distribution that differs from the transistor active region, allowing each area to have the quality needed for its specific function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively enhances the surface withstand voltage by up to 1.4 times, improving the transistor's resistance to voltage without increasing power consumption or impacting transistor performance.
Implementation Method 1
a depletion layer being expanded to reach the second semiconductor region or the third semiconductor region from the fourth semiconductor region by applying a voltage to the fourth semiconductor region
Data Source
AI summary
A semiconductor memory device includes an n-type source/drain formed in a surface region of a p-type active region, and a gate. The semiconductor memory device also includes a withstand voltage improvement layer provided with a preset distance maintained from at least one end of the source/drain. N-type impurities are diffused in the withstand voltage improvement layer, and a withstand voltage improvement voltage is applied to the withstand voltage improvement layer to expand a depletion layer to reach the source/drain, so that the maximum withstand voltage value of a transistor is increased.